PharmacoPhotonics (DBA FAST, Inc.) proposes Fast-Track research to determine GFR in its first human Pilot study. The long-term goal of this SBIR project is to test FAST's minimally invasive catheter based fluorescent device in humans and commercialize this device for rapid detection and quantification of glomerular filtration rate (GFR) in patients with acute kidney injury (AKI) and/or chronic kidney disease (CKD). AKI remains a vexing clinical problem resulting in unacceptably high patient mortality, development of CKD and enhanced progression to end stage renal disease. FAST has developed the FAST GFR SystemTM, a minimally invasive technique for direct measurement of GFR. In CKD patients, the estimated GFR (eGFR) method for determining baseline GFR and following disease progression and response to therapy has proved to be a disappointment. Having a rapid point of care ability to measure GFR (mGFR) would greatly improve patient stratification, management and evaluation of therapies. The System is intended as an adjunct to current methods utilized to assess renal function. This System has been successfully tested under physiologic and AKI conditions in dogs, and shows a close correlation with a research gold standard measure of GFR. Based upon this success, FAST proposes to test the FAST GFR SystemTM device in humans (Phase I Specific Aim 1) for determination of GFR and plasma volume, under an FDA- Investigational Device Exemption (IDE) Pilot Human Trial (A). GFR will be determined in eight (8) healthy volunteers in order to evaluate system safety and efficacy as compared to iohexol clearance, establish human dosing and testing parameters, and evaluate the pharmacokinetic profile of the intravenously injected visual fluorescent injectate. Based on the success of Phase I, FAST will then test the FAST GFR SystemTM for determination of GFR and plasma volume, under an FDA-IDE for a Pilot Human Trial (B) in Phase II Specific Aim 1. GFR will be determined in a total of twenty-four (24) subjects with widely varying renal impairment, including AKI, to allow for evaluation of safety and efficacy over the spectrum of GFRs seen in kidney disease. This FAST GFR SystemTM method is of major clinical importance in AKI and CKD patients, especially in high risk patients where intense surveillance is necessary for early diagnosis, stratification by severity, and response to therapy. Furthermore, this new technology for rapid measurement of GFR will for the first time permit early dynamic assessment of kidney function in multiple animal models of human disease; thus expanding scientific knowledge regarding the role of kidney function during early disease onset.